There are conventional transportation systems in which articles are transported by a transportation vehicle such as an overhead transportation vehicle.
For example, a semiconductor plant for manufacturing semiconductor devices is divided into areas for different processes. Each of the areas is referred to as a bay and has a circuit track along which overhead transportation vehicles travel around unidirectionally.
Each of the transportation vehicles travels along the circuit track to transport articles such as wafers, which are material for semiconductor devices, to a manufacturing apparatus in the bay. The transportation vehicles therefore stop at a predetermined position. PTL 1 discloses a technique to stop an overhead traveling vehicle (transportation vehicle) at a stop position.